Safety edge mechanism for doors



July 1l, 1957 B. J. eRocKMx-:YER ETAL SAFETY EDGE MECHANISM FOR DOORS Filed Dec. so, 1965 5 Sheets-Sheet 1 July 11', 1967 Filed Dec. 30. 1965 B. J. BROCKMEYER ETAL SAFETY EDGE MECHANISM FOR DOORS 5 Sheets-Sheet. 2

FIGB

July 11, 1957 B. .1. BROCKMEYER ETAL 3,330,923

SAFETY EDGE MECHANISM FOR DOORS 5 Sheets-Sheet 5 Filed Dec. 30, 1965 July 11, 1957 B. J. BRocKMEYER E'rAL 3,330,923

SAFETY EDGE MECHANISM FOR DOORS Filed nec. so, 1965 5 sheets-Sheet 4 l INVENTORS BERNARD J. BROCKMEYER Q MALVERN A ScHwelG BYMM v1.6.6#

ATTORNEYS July 11, 1967' a. .1. BROCKMEYER ETAx. 3,330,923

SAFETY EDGE MECHANISM FOR DOORS Filed Dec. 30, 1965 5 Sheets-Sheet 5 FIG. 5

INVENToRs BERNARD J. BROCKMEYER MALVERN A. SCHWEIG ATTO R N EYS United States Patent ABSTRACT F DISCLOSURE Safety edge mechanism for power operated doors, such as are used with elevators and the like, comprising a trip wire member mounted in the leading edge of the closure or door so as to be sensitive to obstructions and in a position to sense the presence of an obstruction. The trip member is coordinated with an electrical circuit having control switch means mounted on the power operated closure so that switch actuator means carried on the closure may be operably connected to the trip member to respond to its movement for activating the control switch means so that the power applied to closing the closure may be immediately applied to the opening operation of the closure. The apparatus is so coordinated that the actuator means may have a neutral setting so as to permit the switch means to be unactivated when there is minimum tension in the trip member, and in such a coordinated arrangement the actuator means may move in a lirst direction to activate the control switch means when the tension in the trip member increases, such as upon meeting an obstruction, and may move out of the neutral setting in a different direction than the first mentioned direction to activate the switch means when the tension decreases to something less than the minimum tension, .as for example when the trip wire breaks. It is understood that actuation of the control switch means includes operating or permitting theV switch means to operate from one position to another position, because in certain arrangements the switch means will be wired for normally closed or normally opened positions and activation would mean reversing what is considered normal.

This invention relates to safety edge mechanisms for power operated doors, and more particularly to safety edge mechanisms for opening and closing vertical and horizontal closures, such as doors, gates, bi-parting doors and gates, etc. More specifically this invention relates to safety edge mechanisms for such closures that include fail safe features to keep the closures from closing under power if the safety edge mechanism becomes damaged and inoperative.

Heretofore motor driven doors have been designed with various safety edges to stop or reverse the closing action of the doors whenever the edge engaged an obstruction which otherwise would jam the door and often damage or injure the thing or person obstructing the closing of the door, as well as overheat the motor.

These prior designed doors utilize either a trip wire mechanism or a mechanically folding mechanism which, under deflection, activated a switch to stop or reverse the door closing operation. Safety edges of various designs for such doors do not provide protection should the edge become inoperative to stop or reverse the door closing. Moreover, most all such doors utilize limit switches to stop the door motor after completion of the door opening or closing operation. Such limit switches are ineffective with present door control arrangements to prevent tripping of the safety edges when the doors are fully closed and causing the door to open` The present invention affords additional safety features not provided by prior closure construction. Briey, the

3,330,923y Patented July lil,

present invention provides a vertical or horizontal moving closure such as doors, gates, bi-parting doors, etc. which incorporate a safety edge mechanism having a fail safe arrangement. The closure in accordance with the invention includes a trip member stopping or reversing feature, as well as a fail safe feature that prevents closing the closure if the trip member is not functioning because of being slack or broken. The safety edge mechanism is a low mass system utilizing a minimum tension on the trip member. Any additional tension occurring by the closure engaging an obstruction activates an electrical switch in the safety edge mechanism that interrupts the control circuit which may either stop or reverse the closing operation of the closure. Likewise, if the minimum tension on the trip member is not maintained because of the trip member breaking or otherwise becoming slack, the control circuit is interrupted and the closure can not be closed but will either remain stopped or move to the fully open position. Moreover, the safety edge and fail safe mechanism activate the closure opening operation through an electrical circuit in series with a close limit switch such that whenever the closure is fully closed, it is impossible to start the operating motor and open the door by triggering the safety edge mechanism. Consequently, the invention provides a reliable, positive acting, low mass, highly sensitive safety edge closure with a fail safe feature.

It is therefore an important object of the invention to provide a safety edge for a door which edge is simple and easy to construct and which provides a safety edge mechanism with a fail safe feature.

It is another object of the invention to provide a safety edge door which when fully closed can not be operated by tripping the safety edge mechanism.

It is another object of the invention to provide a safety edge closure for both vertical and horizontal operation which has a minimum of operating elements and which includes a fail safe arrangement.

It is a further object of the invention to provide a safety edge closure which has a low mass safety edge mechanism including a reversing or stop switch and a fail safe switch, either switch, when activated, interrupts the closing operation circuit of the closure and may or may not complete the opening operation circuit of the closure.

It is a further object of the invention to provide a safety edge for a door with a low mass trip wire mechanism which is activated when the door engages an obstruction `and deilects the trip wire, or when the trip wire is slackened or broken.

It is still a further object of the invention to provide v a motor driven door with a safety edge mechanism which incorporates a trip wire that activates an interrupt switch in the door closing circuit of the motor whenever the trip wire is deflected and activates an interrupt switch in the door closing circuit of the motor whenever minimum tension is not maintained on the trip wire.

These and other objects and advantages of the invention will become readily apparent from the ensuing description taken in conjunction with the appended claims and the drawings wherein:

FIG. 1 illustrates, partly broken away, one embodiment of the safety edge mechanism in a horizontally closing and opening door;

FIG. 2 illustrates, partly broken away, another embodiment of the safety edge in a vertically closing and opening door; I

FIG. 3 illustrates an electrical circuit arrangement for a motor driven door utilizing the invention;

FIG. 4 illustrates another embodiment of the invention;

FIG. 5 illustrates swivel ment in FIG. 4; and

guide member for the embodiwhen the term door is used, refers to all types of clo- Referring now to the drawing and particularly FIG. 1, a horizontally opening and closing door, utilizing the safety edge mechanism of the invention, includes a safety edge 2. The safety edge 2 is provided adjacent the le-ading panel 3 for `door 1. At the upper'edge of door panel 3, a contact-housing 5 is provided. The housing 5 includes a support plate 6 and U-shaped frame 7. A bell crank 8 is pivotally mounted o'n support plate'6 by a pivot pin 9 and secured by washers and a cotter pin. One lever arm 11 of bell crank 8 has an aperture which threadedly receives an actuator bolt 12 adjustably secured therein by a setscrew. The other lever arm 14 of bell crank 8 has an aperture which threadedly receives an eye bolt 15 therethrough adjustably secured therein by ay set screw. A safety edgeswitch 16 is secured to support plate 6 with its `actuator adjacent the head of actuator bolt 12. yA fail safe switch 17 is secured to a support bracket 18 that is mounted on support plate 6, and has its actuator adjacent the end of eye bolt 1-5. Eye bolt 15 'extends' through frame 7 and into safety edge 2. A compression spring 19Vis provided for eye bolt 15 between Vframe 7 and the lever arm 14 of bell crank 8,V and urges the end of eye bolt 15 toward the actuator on fail safe switch 17. Both the fail'safe and safety ed'ge switches are preferably they well known microswitch type. The counterclockwise (as viewed in FIG. 1) overtravel o-f lever arm 11 toward the actuator of safety edge switch 16 is limited by vtravel stop bolt 21 threadably received in frame 7 and adjustably locked by lock nut 22. The clockwise overtravel of lever arm 14 towards the actuator of fail safe switch 17 -is limited by travel stop bolt 23 threadably received in frame 7 and adjust-ably locked byv lock nut 24. One end of a tension spring 27 is hooked into theV eye of eye bolt 15. A trip-wire 28 has one end formed in a loop 29 which is secured by a wire clamp 31. The other end of tension spring 27 is hooked into loop 29. In order to secure the other end of trip wire 28 near' the bottom of flexible sheath 25, a dead end bracket 32 is provided. The dead end bracket 32 includes two right angle brackets 33 secured to the lower edge of door panel 3 by screws. Angle brackets 33 have apertures with bushings 34 therein. A pivot pin 35 is providedV in bushings 34, and pivotally secures a dead end arm 36 to angle brackets 33. The dead endA arm 36 extends downwardly and outwardly from angle brackets 33 towards the outermost bottom edge of flexible sheath 25. One end of dead end arm 36 abuts the lower edge of door panel 3, and thus has limited clockwise travel. The other end of dead end arm'36 forms a foot 37 which has an aperture 38 therein. The lowerend'of trip wire 28 is passed through the eye of an eye bolt 39 and securedfin a loop by wire clamp 41. The end of eye bolt 39 is 'received through aperture 38. Angle extension bracket 43 is welded to the bottom of foot 37. Nuts 42 and 44 lock eye bolt 39 in place. The extension bracket 43 is adjacent the bottom outermost edge of flexible housing 25. Nut -42 and nut 44 are threaded onto eye bolt 39 to provide the proper tension on trip wire 2S.

The trip wire 28 may be music wire or other suitable wire preferably of high tensile strength and low mass. Also, the wide may have solid members or springs interspersed along its length. The entire safety edge mechanism is a low massv system which provides quick response to the smallest forces being applied to the trip wire. To achieve full advantage of the low mass system, the safety edge mechanism initially must be properly adjusted,rh'ow ever,` the adjustment is quite simple. Fail safe travel stop 23 is set to permit complete actuation of the switch plus a few thousandths overtravel without allowing the actuator to bottom in the switch. Safety edgeY travel stop bolt 21 is adjusted to allow sufficient movement to actuate the safety edge switch plus several thousandths overtravel without allowing the actuator to bottom in the switch, The safety edge switch and fail safe switch are wired in the electrical motor control circuit in series or series parallel as later described in conjunction with FIG. 3.

The safety edge mechanism, in operation, is sensitive to nominal increases or decreases in tension on the trip wire 28. Consequently, on closing of the door any obstruction which safety edge 2 engages, deflects trip wire 28 tending to increasetension on the trip Vwire-and causing compression spring 19 to be compressed. Under deflection of trip wire 28, bell crank 8 rotates counterclockwise causing actuator bolt 12 to depress the actuator of safety edge switch 16 and actuate the safety edge switch. The lever arm 14 of bell `crank 8 engages travel stop 21. In this condition, :fur-l ther deflection of trip wire 28 expands tension spring 27. Activation of safety edge switch 16 stops or reverses the closing operation -of horizontal door 1. When the obstruc tion no longerengages safety edge 2, trip wire 28 moves backrinto proper position. If the obstruction is near the bottom edge of door 1, dead end arm 36 rotates counterclockwise in the plane of the door about pivot pin 35 deflecting trip wire 28. If for any reason trip wire 28 does not return to the proper tension, compression spring 19 will rotate bell crank 8 clockwise moving eye bolt 15 into engagement with .the actuator of fail safe switch 17 activating the fail safe switch to stop or reverse the closing operation of the door 1. Furthermore, should trip wire 28 stretch or break, fail safe switch 17 is activated interrupting the closing circuit of door 1.

Referring to FIG. 2 an embodiment of a vertical opening and closing door or gate 45 incorporating the safety edge mechanism with fail safe feature is illustrated. A contact housing 46 is mounted at the bottom left side (as viewed in FIG. 2) of the vertical door or gate 45. The contact housing 46 includes a supportY plate 47 and ya U- shaped frame 48, as well as a cover 50. A switch lever 49Vis pivotally mounted to support plate 47 by pivot pin 51. A travel stop bolt 52 is threadably'received through an aperture in frame 48 and locked by lock nut 53. The travel stop bolt 52 is at one end of lever 49.l An eye bolt 54 is threadably received and locked with a set screw in the other end of lever 49. An actuator bolt 55 is provided adw to safety edge 2. A relatively heavy spring biases lever 49 with actuator bolt 55 towards the actuator of safety edge switch 59. A switch housing 62 is mounted at the bottom right side (as Viewed in FIG. 2) of the vertical door or gate 45. The switch housing 62 includes a mounting plate 63 and a U-shaped bracket 65. A switch arm 66 is prvotally attached'to mounting plate 63 by piv-ot pin 67. A travel stop bolt 68r is threadably received through an aperture in bracket 65 and locked in place by lock nut 69. The travel stop bolt is at one end of switch arm 66. An

eye bolt 71 passes through an aperture in bracket 65 andf i mounting place 64 with the switch actuator opposing the head of operator bolt 72. A set screw 76 secures operator bolt 72 to arm 66. The eye bolt 7.1 projects into safety edge 61, similar to safety edge 2. A relatively light spring 77 iases switch arm 66 along with operator bolt 72 towards the actuator of fail safe switch 75, but spring 77 is held in a compressed position, with switch arm 66 against stop bolt 73, by the tension of heavier spring 60. One end of a tension spring 78 is hooked into the eye of eye bolt 71. The other end of tension spring 78 is attached to one end of a trip wire 79. The trip wire may be any suitable wire, such as music wire, and may or may not he interspersed with solid members and springs. The other end of the trip wire 79j is attached through the eye of eye bolt 54. The safety edge 61 is covered by a flexible sheath 80.

The safety edge mechanism, as noted heretofore, is a low mass system which operates with the slightest increase or `decrease in tension on the'trip wire. Thus, the slightest deflection of trip wire 79 caused by safety edge 61 engaging an obstruction is .suilicientl To achieve full advantage ofthe low mass system, the safety edge mechanism initially must be properly adjusted, however, the adjustment is quite simple. First, light spring 77 and heavy spring 60 are balanced against each other and tension spring 78 such that switch arm 66 is held against arm stop bolt 73; switch lever 49 is held against travel stop bolt 52; and tension spring 78 is fully contracted. The sensitivity of the safety edge mechanism depends on the setting of the amount of travel by actuator =bolt 55 to release safety edge switch 59. This adjustment may be made by screwing actuator bolt 55 in or out. Actuator adjustment of fail safe switch 75 may be made by screwing actuator bolt 72 in or out. Travel stop bolt 68 is -adjusted to allow operator bolt 72 to operate the actuator of fail safe switch 75 with a few thousandth overtravel, when the trip wire 79 is slack.

Operation of vertical opening and closing door or gate 45 during closing operation when an obstruction engages safety edge 61 is quite similar to the operation of safety edge 2 of horizontal door 1. Thus, when trip wire 79 is deflected by the safety edge striking an obstruction, eye bolt 54 rotates switch lever 49 counter-clockwise moving actuator bolt 55 away from the actuator of safety edge switch 59 transfen'ng the contacts of switch 59. Of course, during deflection of trip wire 79, switch arm 66 will not rotate as arm 66 is normally held against arm stop bolt 73. If the deflection of trip wire 79 causes switch lever 49 to engage lever stop 'bolt 57, any further deflection of trip wire 79 will expand tension spring 78. Activation of the safety edge switch 59 stops or reverses the closing operation of vertical door or gate 45. When the obstruction no longer engages safety edge 61, trip wire 79 moves back into proper position. Of course, the contact housing 46 and switch housing 62 at the edges of door or gate 45 are not within the open area closed by the door 45, hence, do not normally engage obstructions.

Referring now to FIG. 3, 'a typical door'operating circuit incorporating the invention will be described. The circuit includes a power disconnect device 81 which supplies three phase power to door opening contacts 83 and closing contacts 84. The opening contacts 83 and closing contacts 84 supply the three phase power through overload heaters 85 to motor 86 which may or may not have an associated brake. Disconnect device 81 also supplies single phase power to control transformer 87. Control transformer 87 provides power through stop button 88 and overload contacts 89 to opening control circuit 90 and closing control circuit 91.

The opening control circuit includes an open button or switch 92 with holding contacts 93, an open limit switch 94, an electrical interlock 95 and opening relay coil 96. Thus, when open switch 92 is momentarily depressed, holding contacts 93 complete the opening holding circuit through opening relay coil 96 which activates opening contacts 83. Contacts 83 supply power to motor 86 of the proper phases for opening the power door, such as door 1 or door 45. After the power door is fully open, open limit switch 94 breaks the opening circuit 90.

The closing control circuit includes a close button or switch 97 with associated holding contacts 98, a close limit switch 99, a safety edge switch device (which for example, may be the series or series parallel connection of the fail safe switch 17 or 75 and the safety edge switch 16 or 59 appertaining to the present invention as described in conjunction with either FIG. 1 or FIG. 2, or the combination switch 148 described in conjunction with FIG. 6), an electrical interlock 101 and closing relay coil 102. In the normal door closing sequence, when close switch 97 is momentarily depressed, holding contacts 98 complete the closing holding circuit 91 from control transformer 87 through stop button 88, close limit switch 99 and safety edge switch device 100 to one side of closing relay coil 102, the other side of relay coil 102 being connected through overload contacts 89 to the control transformer. The relay coil 102 when energized actuates closing contacts 84 to supply power to motor 86 of the proper phases for closing the power door, such as door 1 or door 45. Should an obstruction in the power door strike the safety edge or should the safety edge trip wire mechanism be disabled, the safety edge switch device 100 will break the closing circuit and de-energize the closing relay coil 102 and the holding contacts 98 which Will stop the door. However, the parallel circuits of the switch device 100 and the close limit switch 99 in series therewith form a parallel circuit which by-passes the open button 92 and holding contacts 93 whenever the safety edge switch device 100 is activated by its normal or fail safe feature. Consequently, when activated, safety edge switch device 100 energizes opening relay coil 96 and holding contacts 93 to fully open the power door.

The series connection of close limit switch 99 and -switch device 100 is such that close limit switch 99 disables safety edge switch device 100 whenever the power door is fully closed, hence prevents energization of the opening circuit of the power door by tampering with the safety switches 100 whenever the power door is fully closed.

Referring to FIGS.' 4 and 5, another embodiment of a vertical opening and closing door or gate incorporating the safety edge mechanism with fail-safe feature is illustrated. The vertical door 110 has integral support extensions 111 and 112. A pulley link 113 is pivotally mounted at the extreme edge of support extension 111. The pulley link 113 supports a pulley wheel 114 at the free end thereof. The free end of support extension 112 rigidly supports a pulley block 116 having a pulley wheel 117. It -will be appreciated that either or both pulley sity of a pulley wheel. For purposes of simplicity, door 110 is described utilizing contact housing 46 mounted adjacent support extension 111, and contact housing 62 mounted adjacent support extension 112. Contact housings 46 and 62 in all respects are identical as illustrated in FIG. 2. However, it will be noted in FIG. 4 that the contact housings 46 and 62 are rotated 90 degrees with respect to the illustration in FIG. 2. Likewise, the safety edge switch arrangement in contact housing 46 and the fail safe switch 75 arrangement in contact housing 62 is fully described in connection with FIG. 2 and further desorption thereof is unnecessary. Of course, it will be appreciated that the contact housing 5, including the safety edge switch 16 arrangement and the fail safe switch 17 arrangement, could be used in conjunction with door 110, in which case lcontact housing 5 would replace either contact housing 46 or conta-ct housing 62, and the remaining contact housing lwould be replaced by a dead end arrangement.

Door 110 has a trip member 118, which may be similar to trip wire 79, extending along ,the safetyV edge 119. and over pullley wheels 114 and 117. The end of trip member 118, illustrated near pulley wheel 114, is formed into a loop 120 .which is secured by a clamp 121A tension spring 122 connects loop 120 of trip member 118 to the eye bolt 54 of contact Ihousing 46. The other end of trip member 118 near pulley 117 is passed through the eye of eye bolt 71 and secured by a clamp 123. The tension of trip member, 118 is adjusted identically as described with respect to trip wire 79 of door 45 illustrated in FIG. 2. A flexible sheath 124 provides a covering for the safety edge 119. It will be understood that whenever tension on trip member 118 varies from a pre-set value the safety edge switch or fail safe switch will be activated to interrupt the closing operation-of door 110. Consequently, Vshould trip member 118 become slackened or broken the closing operation of the door will be interrupted by the fail safe switch, and optionally the door 110 willbe fully opened.. Likewise, should safety edge 119 strike an obstruction in the door path of door 110, trip member 118 will be deflected tending to increase tension and `activate the safetyedge switch to interrupt the closing operation of the door. Excessive defiection of trip member 118 is absorbed by tension spring 122 to avoid damage to the trip member. It will be appreciated that the pulley pivot arm 113 pivots in the plane of the door. Also, pulley block 116 could be replaced with a pully pivot arm similar to pivot arm 113. Y

Referring to FIG. illustrating a detail modification to door 110, a` swivel link 125,4 which could be a simple wire, securesa hollow axle pulley 126 to support extension 111 of vertical door 110. This arrangement provides a directional guide for tension rmember 118- similarly as pulley wheels 114 and 117. Thus, the lateral deflection of the trip member 118 with respect to the plane of the door 110 will permit swivel link 125 to swivel with the pulley wheel 126 and thus aid to increase the tension on trip member 118 sufficiently to trigger the safety edge switch. Y Referring now to FIG. 6, another embodiment of the safety edge switch and 'fail safe switch arrangement is illustrated. The contact housing 130 .similar to contact housing 5 is illustrated having a support plate 131 and a U-shaped frame 132 fastened thereto. A` lever 133 is pivotally mounted on support plate 131 by pivot pin 134 and secured by washers and a cotter pin. One arm 135 of lever 133 has an aperture which receives an actuator bolt .136 adjustably secured therein by a set screw. The other arm 137 of lever 133 `has an aperture therein which receives an eye bolt 138 adjustably secured therein by a set screw. A combination safety edge and fail safe switch assembly 139 is secured to a mounting plate 140 which is secured to support plate 131. The switch assembly 139 includes integral sides 141 and 142. An actuator arm 143 is supported for sliding movement in slots provided in sides 141 and 142. The arm has a reduced portion 144 whichfretains a biasing spring 145. The actuator arm 143 has a notch 146.7A fiat spring contact arm 147 is secured to side 142 of switch assembly 139, and'extends past the switch contact of a combinationsafety edge and fail safe switch. The free end of arm 147 is rounded toV mate with notch 146. The spring action Vof arm 147 bia-ses the free end of this arm toward notch 146 and out of engagement with the contact of switch 148. The end of actuator arm 143 abuts actuator bolt 136. Spring 145V biases arm 143`toward actuator bolt 136. A compression spring 149 appl-ies tension to the trip member (not shown) secured to eye bolt 138, and thus biases actuator bolt 136 to move away from arm 143.V As viewed in FIG.Y 6, a travel stop bolt 150 limits counterclockwise rotation of lever arm 135 under increased tension on the trip member (not shown) and a travel stop -bolt 151 limits clockwise rotation of lever arm 135 under decreased tension of the trip member. While the notch 146 and arm 147 activated. Should tension on the trip member move eye bolt .138 and lever 133 against the compression of spring 149, actuator bolt 136 will be rotated counter-clockwise as viewed in FIG. 5 and drive Iactuator arm 143 to the left causing spring contact 147 to be forced out of notch 146 and act-nate switch 148. Travel stop bolt 150 prevents damage to switch assembly 139 by excess tension on the trip member. The trip member is protected by a tension spring (not shown). Moreover, should tension on the trip member (not shown) connected to eye bolt 138 become slackened or should the trip member break, compression spring 149 will rotate lever 133 clockwise (as viewed in FIG. 5), moving arm 13S 'againstY travel stop bolt 151 and allow contact arm 143 to be driven to the right under the influence of spring to force spring contact 147 out of notch 146, thus actuating switch 148. The travel stop bolt 151 prevents damage to switch assembly 139 from excessive travel of contact arm 143.

It will be appreciated from the foregoing that the invent-ion provides a safety edge mechanism with a fail safe feature for a power -operated closure such as a door ory gate,v etc. The safety edge mechanism operates to stop or stop and reverse the closing operation of the power operated closure should the safety edge strike an obstruction or should be safety edge be damage and disabled. Moreover, the safety edge power operated closure utilizes a tamper proof closing circuit wherein the close limit switch disables the safety edge mechanism whenever the power door is fully closed. Because of the linkage and make-up of the lDrip member device, it should be noted that along its flexible length the field of operation of the trip member encompasses la full 360 minus that small angle which is occupied bythe door section. Thus, such field would be at least 270. Furthermore, the devices shown in the drawings can be used singly or in multiple for horizontal or vertically traveling doors and gates and can also be used with a rigid dead end hitch for closures depending or door lap and jamb, head and sill condition-s. It isevident that the term powered closure or power operated closure, as used in the foregoing, is meant lto encompass any type of power such as electrical, hydraulic, air, etc., which can be utilized t-o move the closure and relies on an electrical control circuit for initiation of operations.

Moreover, many modifications will be appreciated from the foregoing, such as the use of slave relays with the safety edge and fail safe switches in series with the coil; slave relays energized'from the close button through series connections ofthe safety edge and fail safe switches in which the close direction coil could only be energized when theV fail safe and safety edge switches are in their normal position and the close button or contact is closed.

`Furthermore, contact housing may be mounted up`farther in the door proper and the trip wire can operate around a small pulley on an extension arm to minimize vention which is limited only as defined by the appended claims. i

What is claimed is:

of the device atr the side -1. In a safety edge mechanism for a power operated closure, a closure having a leading edge, power means to openandclosesaid closure, an elongated trip element operably mounted along the leading edge of said closure to be displaced upon striking an obstruction, a -pair of switches carried by said closure at the same end of said trip element, a control circuit wired into said power means and said pair f switches, said circuit including a closure opening portion and a closure closing portion and said switches being connected into said control circuit portions to change the power means from said closure closing portion to energize said closure opening portion, and switch operating pivoted arms means connected between said trip element and said switches said trip element being connected to said pivoted arm adjacent one switch normally to actuate the other switch upon displacement of said Itrip element and said switch operating pivoted arm means including resilient means bearing on said pivoted arm adjacent said one switch and available to actuate said one switch upon breakage of said trip element.

2. The safety edge mechanism set forth in claim 1 wherein said trip element includes a lresilient member opposing said resilient means bearing on said pivoted arm.

3. The safety edge mechanism set forth in claim 1 and including resilient power means engaged with said switch operating means to operate said other switch on breakage of said trip element, and said trip element including a resilient member adapted to maintain said trip element under tension and normally over-power -said resilient power means.

4. The safety edge mechanism set forth in claim 1 wherein said switches are disposed adjacent opposite ends of said elongated trip element and said switch operating means includes a pivoted arm at each switch and a resilient means bearing upon each arm to normally displace said arms in switch -actuating directions, said elongated trip element being connected to said pivoted arms to oppose said resilient means.

5. The safety edge mechanism set forth in claim 4 10 wherein one of said `resilient means is stronger than the other, and said elongated trip element includes a resilient member opposing both of said resilient means.

6. A safety edge mechanism for a power operated closure to interrupt the closing operation of the closure comprising in combination: a closure having a leading edge, a source of power ope-rating said closure, a trip member extending along the leading edge of said closure, control switch means connected into said source of power and responsive upon activation to interrupt the application of power to the closing operation of said closure and to apply the power to the opening operation of said closure, actuator means attached to said closure and operably connected to said trip member to respond to movement of said trip member for activating said control switch means to interrupt the power for the 4closing operation and to apply the power to the opening operation of said closure', and biasing means coacting with -said trip member and actautor means to maintain said actuator means in a neutral setting permitting said switch means to be unactivated under a minimum tension in said trip member, said actuator means moving in a rst direction out of said neutral setting to -activate said control switch means upon tension on said trip member increasing from said minimum tension and moving out of said neutral setting in a direction different from said first direction to activate said control switch means whenever the tension in said trip member decreases to a value less than said minimum tension.

References Cited UNITED STATES PATENTS 1,944,157 1/1934 Forman 20G-61.43 2,610,268 9/1952 Hamilton 20G-61.43 3,001,038 9/1961 Gesell ZOO-61.43 3,159,728 12/ 1964 Urquhart 20D-61.43

BERNARD A. GILHEANY, Primary Examiner. H. E. SPRINGBORN, Assistant Examiner. 

6. A SAFETY EDGE MECHANISM FOR A POWER OPERATED CLOSURE TO INTERRUPT THE CLOSING OPERATION OF THE CLOSURE COMPRISING IN COMBINATION: A CLOSURE HAVING A LEADING EDGE, A SOURCE OF POWER OPERATING SAID CLOSURE, A TRIP MEMBER EXTENDING ALONG THE LEADING EDGE OF SAID CLOSURE, CONTROL SWITCH MEANS CONNECTED INTO SAID SOURCE OF POWER AND RESPONSIVE UPON ACTIVATION TO INTERRUPT THE APPLICATION OF POWER TO THE CLOSING OPERATION OF SAID CLOSURE AND TO APPLY THE POWER TO THE OPENING OPERATION OF SAID CLOSURE, ACTUATOR MEANS ATTACHED TO SAID CLOSURE AND OPERABLY CONNECTED TO SAID TRIP MEMBER TO RESPOND TO MOVEMENT OF SAID TRIP MEMBER TO RESPOND TO MOVEMENT OF TO INTERRUPT THE POWER FOR THE CLOSING OPERATION AND TO APPLY THE POWER TO THE OPENING OPERATION OF SAID CLOSURE, AND BIASING MEANS COACTING WITH SAID TRIP MEMBER AND ACTAUTOR MEANS TO MAINTAIN SAID ACTUATOR MEANS IN A NEUTRAL SETTING PERMITTING SAID SWITCH MEANS TO BE UNACTIVATED UNDER A MINIMUM TENSION IN SAID TRIP MEMBER, SAID ACTUATOR MEANS MOVING IN A FIRST DIRECTION OUT OF SAID NEUTRAL SETTING TO ACTIVATE SAID CONTROL SWITCH MEANS UPON TENSION ON SAID TRIP MEMBER INCREASING FROM SAID MINIMUM TENSION AND MOVING OUT OF SAID NEUTRAL SETTING IN A DIRECTION DIFFERENT FROM SAID FROM DIRECTION TO ACTIVATE 